lua-oocairo-fontopt(3) [debian man page]
doc::lua-oocairo-fontopt(3) Lua OO Cairo binding doc::lua-oocairo-fontopt(3) Name lua-oocairo-fontopt - options controlling text rendering Introduction A font options object contains options that tell Cairo how to render text on surfaces. They can be created with the "font_options_create" function in the main oocairo module (see lua-oocairo(3)), and retrieved from scaled fonts or context objects with "get_font_options" methods. Font options objects can be compared with the "==" operator. Two different objects with the same options set will be considered equal. Methods The following methods are available on font options objects: opt:copy () Returns a new font options object, with identical options to opt. The two objects will be completely independent, so you can set them to have different options. opt:get_antialias () Get the current antialiasing mode, which will be one of the strings accepted by the "opt:set_antialias()" method. opt:get_hint_metrics () Returns the current hint metrics option, which will be one of the same strings accepted by the "opt:set_hint_metrics()" method. opt:get_hint_style () Get the kind of font hinting done when rendering text. Returns one of the strings accepted by the "opt:set_hint_style()" method. opt:get_subpixel_order () Returns the current ordering of colour components in pixels used for subpixel rendering, which will be one of the same strings accepted by the "opt:set_subpixel_order()" method. opt:hash () Return a number which can be used as a hash key identifying the particular options in opt. That is, if you wanted to cache fonts according to the options set on them, you could store them in a table with this hash value as the key. Two font options objects with the same options will have the same hash value. opt:merge (srcopt) Add any options which are set to a non-default value in srcopt to opt if that still has the default value from them. The options in srcopt will be unchanged. Nothing is returned. opt:set_antialias (antialiastype) Set the antialiasing mode used for drawing. The argument must be a string or boolean value accepted by the "set_antialias" method on context objects (see lua-oocairo-context(3)). opt:set_hint_metrics (hintmetrics) Set the kind of hinting to be applied to the metrics, as opposed to outlines, of the glyphs in a font. The hintmetrics value must be one of the following strings: default off on opt:set_hint_style (hintstyle) Set the kind of font hinting done when rendering text. The hintstyle value must be one of the following strings: default none slight medium full opt:set_subpixel_order (order) Used to inform Cairo of the arrangement of colour components in the pixels of a display device like a monitor. Only applies if subpixel antialiasing is used. The order value must be one of the following strings: default rgb bgr vrgb vbgr The last two options refer to vertical arrangements of colours. 1.4 2011-05-18 doc::lua-oocairo-fontopt(3)
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doc::lua-oocairo-scaledfont(3) Lua OO Cairo binding doc::lua-oocairo-scaledfont(3) Name lua-oocairo-scaledfont - Scaled font face object Introduction Scaled font objects represent Cairo font faces which have been scaled to a particular point size. They can be created from a font face object with the "scaled_font_create" function in the main module table (see lua-oocairo(3)), or the "get_scaled_font" method on context objects (see lua-oocairo-context(3)). Scaled font objects can be compared with the "==" operator. This will compare the identity of the objects, so different Lua objects which refer to the same "cairo_font_face_t" will compare as equal. Methods Scaled font objects provide the following methods. font:extents () Returns a table containing metrics information about the font. The return value is in the same format as that of the "font_extents" method on context objects (see lua-oocairo-context(3)). font:get_ctm () Returns the coordinate transformation matrix (CTM) associated with the font. This maps user coordinates into device coordinates on the surface with which the font is used. See lua-oocairo-matrix(3) for details of the return value type. font:get_font_face () Returns an object representing the unscaled font face used to create this font. See lua-oocairo-fontface(3) for details of its methods. font:get_font_matrix () Returns the matrix representing the scaling of the font into user coordinates. See lua-oocairo-matrix(3) for details of the return value type. cr:get_font_options () Returns a font options object (see lua-oocairo-fontopt(3)) containing the rendering options that were supplied when creating this font. font:get_scale_matrix () Returns a matrix table representing the scaling of the font to the coordinate space of the surface it is used on. This is the matrix obtained by multiplying the font matrix by the surface CTM. See lua-oocairo-matrix(3) for details of the return value type. Only available with Cairo 1.8 or better. font:get_type () Returns a string indicating which back-end library provides the font face information. The return value will be one of the same strings returned by the "get_type" method on a font face object (see lua-oocairo-fontface(3)). font:glyph_extents (glyphs) Same as "font:text_extents()", but instead of a string, the glyphs value should be table in the format accepted by the "show_glyphs()" method on context objects (see lua-oocairo-context(3)). font:text_extents (text) Returns a table containing measurements of the given UTF-8 text as it would be rendered in this font. The return value is in the same format as that of the "text_extents" method on context objects (see lua-oocairo-context(3)). font:text_to_glyphs (x, y, text) Given some UTF-8 text in the string text, and starting coordinates of x and y, this works out which glyphs need to be drawn to represent the text, and which glyphs correspond to the bytes in text. The method returns two tables, the first an array of glyphs suitable for supplying to methods like "show_glyphs" and "glyph_extents", and the second is a table of text clusters suitable for supplying to the "show_text_glyphs" method on a context object. Only available with Cairo 1.8 or better. 1.4 2011-05-18 doc::lua-oocairo-scaledfont(3)